CN114756011B - Intelligent home anomaly detection method based on TV-PKEET - Google Patents

Abstract

A smart home anomaly detection method based on TV-PKEET includes the steps: the key generation center generates system public parameters; generating public keys and private keys of the intelligent home equipment and the home control center; generating ciphertext of the real state and the simulation state of the intelligent household equipment; the intelligent home equipment generates an authorized trapdoor for the equipment gateway and sends the trapdoor to the equipment gateway; judging whether the detection result is normal or not according to the two test elements generated by the equipment gateway. The invention solves the problems that the detection result in the prior art is maliciously tampered or forged, and the real/analog state of the intelligent home equipment is transmitted on a public channel, so that the intelligent home equipment is extremely easy to attack from the inside and the outside. The invention can verify straightness by using the TV-PKEET based on the real/analog state of the TV-PKEET encryption equipment, thereby ensuring the reliability of the detection result.

Description

Smart home anomaly detection method based on TV-PKEET

technical field

The invention belongs to the field of physical technology, and further relates to a smart home anomaly based on a cipher text equivalent test TV-PKEET (tester-verifiable public-key encryption with equality test) in the field of testing technology that can be verified by a tester for message consistency Detection method. The invention can be used to solve the problems that the detection results in the prior art are maliciously tampered or forged, and the real/simulated state of the smart home equipment is transmitted on the public channel, which is extremely vulnerable to internal and external attacks.

Background technique

Since smart home devices collect information from the physical environment and the public Internet, and execute commands in combination with predefined constraints, anomalies in IoT-based smart home systems must be considered, and whether they are caused by attacks or device failures. In an anomaly detection system, there is usually a real-world state and a simulated state, simulated according to semantics, predefined constraints, or received commands using machine learning or data mining. An inconsistency between these two states is then determined to be "abnormal". For example, after receiving a "dim" command from a resident, the simulated state of a light should be "off", and if its real state is still "on", it will be detected as "abnormal".

Beijing Jinmao Green Building Technology Co., Ltd. discloses a smart home anomaly detection method in its patent document "A Smart Home Anomaly Detection Method and Device" (application number 202010464430.4, publication number CN111650922A[P]). The implementation steps of the method are as follows: firstly, real-time data will be obtained, and the characteristic curves will be generated according to time; secondly, whether the equipment is in a fault state or a normal state at a certain moment is determined by matching the data characteristic curves; then, if there is a fault , to pass exception status information to the user. The disadvantage of this method is: because the detection results are transmitted in the public channel, the detection results may be maliciously tampered with or forged.

In their paper "Hawatcher: Semantics-aware anomaly detection for appified smart homes" (USENIX Security Symposium 2021:4223-4240), Chenglong Fu et al proposed a semantic-aware anomaly detection method for smart homes. The implementation steps of the method are as follows: first, a semantic-assisted mining method is proposed, which utilizes semantic information to construct hypothesized associations, and uses event logs as evidence to verify these associations; second, since correlations can be interpreted in terms of semantics, It can thus be refined to resolve conflicts with smart applications; the shadow execution engine then uses these dependencies to simulate the normal behavior of a smart home. The simulated state is compared to the real-world state through context checks and result checks, with inconsistencies in the comparison reported as anomalies. The disadvantage of this method is that the real/simulated state of the smart home device is transmitted on a public channel, which is extremely vulnerable to internal or external attacks. For example, an external attacker can use a man-in-the-middle attack to tamper with the state of the device, which will cause an exception The test results lose reliability.

Contents of the invention

The object of the present invention is to propose a TV-PKEET-based anomaly detection method in smart home for the deficiencies of the above-mentioned prior art. It is used to solve the problem that the detection results will be maliciously tampered or forged, and the real/simulated state of smart home devices is transmitted on a public channel, which is extremely vulnerable to internal or external attacks.

In order to achieve the above object, the idea of the present invention is that the present invention encrypts the plaintext message based on the cyclic group and the bilinear mapping, and first uses the random number to perform a power operation on the generator of the cyclic group and the first part of the public key to generate a partial encryption text, use the second part of the public key and random number to randomize the plaintext message, then perform the bilinear mapping operation on the generator and the first part of the public key, and finally synthesize the ciphertext, and compare the real state and the simulated state of the smart home device Encryption, so as to solve the problem of malicious tampering or forgery of detection results existing in the prior art. The present invention calculates the obtained two different ciphertexts to obtain test elements, and then judges whether the two test elements are equal. If they are equal, it means that the plaintexts corresponding to the two different ciphertexts are equal, and verify whether the real state and the simulated state are equal. Consistent, in order to solve the problem that the real/simulated state of the smart home device is transmitted on the public channel in the prior art, and it is extremely vulnerable to internal or external attacks.

Technical scheme of the present invention is as follows:

Step 1, the key generation center generates system public parameters:

The key generation center generates public parameters: Γ={G,G _T ,g _m ,g _n ,p}, where G represents the additive cyclic group generated by the key center with an order of a large prime number p randomly selected, G _T Represents the multiplicative cyclic group obtained by bilinearly mapping the additive cyclic group G, G×G→G _T , g _m represents the mth generator in the additive cyclic group G, and g _n represents the multiplicative cyclic group G _T n generating elements, p represents a coefficient greater than 2 ^λ , and the value of λ is determined according to the security parameters of the cryptographic system used when the key generation center generates public parameters;

Step 2, generate public and private keys for smart home devices and home control centers:

Step 2.1, generate and save the private key of the smart home device: sk={x,y,z}, where x, y, z represent three different positive integers randomly selected in [0,p-1] ;

Step 2.2, generate and disclose the public key of the smart home device: pk=(h ₁ ,h ₂ ,h ₃ ), where h ₁ =g _m ^x , h ₂ =g _m ^y , h ₃ =e(g _m , g _m ) ^z , e(·) represents the bilinear mapping operation;

Step 3, generate the ciphertext of the real state of the smart home device and the simulated state of the smart home control center:

C₄＝e(g_m,h₂)^r+s×h₃，r、s分别表示在[0,p-1]中随机选取的两个不同的正整数，M_R表示智能家居设备的真实状态；Step 3.1, generate the ciphertext of the real state of the smart home device: CT _R ＝{C ₀ ,C ₁ ,C ₂ ,C ₃ ,C ₄ }, where C ₀ ＝g _n ^r , C ₁ ＝g _m ^r ,

C ₄ ＝e(g _m ,h ₂ ) ^r+s ×h ₃ , r and s respectively represent two different positive integers randomly selected in [0,p-1], M _R represents the real state;

C₄′＝e(g_m,h₂)^r′+s′×h₃，r′、s^′分别表示在[0,p-1]中随机选取的两个不同的正整数，M_S表示智能家居控制中心的模拟状态。Step 3.2, generate the ciphertext of the simulated state of the smart home control center: CT _S ＝{C ₀ ′,C ₁ ′,C ₂ ′,C ₃ ′,C ₄ ′}, where C′ ₀ ＝g _n ^r′ , C ₁ '=g _m ^r' ,

C ₄ ′=e(g _m ,h ₂ ) ^r′+s′ ×h ₃ , r′ and s ^′ respectively represent two different positive integers randomly selected in [0,p-1], M _S represents Mock up state of smart home control center.

Send the real state ciphertext CT _R of the smart home device and the simulated state ciphertext CT _S of the smart home control center to the device gateway;

Step 4, the smart home device sends the generated authorization trapdoor to the device gateway:

{g_m,M_R}表示根据智能家居设备真实状态密文生成的测试元，{g_m,M_S}表示根据智能家居控制中心模拟状态密文生成测试元；Step 5, the device gateway generates two test elements,

{g _m , M _R } means the test element generated according to the real state ciphertext of the smart home equipment, {g _m , M _S } means the test element generated according to the simulated state ciphertext of the smart home control center;

Step 6, judging whether the values of the two test elements are equal, if so, then the test result is normal, and then step 7 is executed; otherwise, it indicates that the test result is abnormal, and step 8 is executed;

Step 7, the device gateway uploads the real state ciphertext of the smart home device to the cloud storage;

Step 8, the device gateway sends the detected abnormal result to the smart home control center.

Compared with the prior art, the present invention has the following advantages:

First, because the present invention uses cyclic group and bilinear mapping to implement encryption operations on the real state and simulated state of smart home equipment, the real/simulated state is transmitted in the form of cipher text, which overcomes the problem of the existing technology of real/simulated state. The defect that the detection result is maliciously tampered with or forged due to plaintext transmission makes the present invention have the advantage of being able to protect the real/simulated state information of the device and ensure the authenticity of the test result.

Second, since the present invention receives two different ciphertexts of the device state, it verifies whether there is any abnormality by comparing the ciphertexts, which overcomes the transmission of the real/simulated state of the smart home device on the public channel in the prior art, The disadvantage of being extremely vulnerable to internal or external attacks makes the present invention have the advantage of ciphertext verifiability, which not only helps prevent internal or external attacks, but also ensures the reliability of test results.

After the present invention receives the ciphertext of the real state and the simulated state of the device, it compares whether the encrypted states are equal through the modules embedded in the state in the two ciphertexts, so as to verify whether there is any abnormality in the device, and overcomes the problem of using existing similar technologies. The defect that the comparison result does not match the encrypted state makes the present invention have the advantage of guaranteeing the reliability of the anomaly detection result.

Description of drawings

Fig. 1 is the realization flowchart of the present invention.

Detailed ways

The implementation steps of the present invention will be further described in detail below in conjunction with the accompanying drawing 1 and the embodiments.

Step 1, the key generation center generates system public parameters.

The key generation center generates public parameters: Γ={G,G _T ,g,g _T ,p}, where G represents the additive cyclic group generated by the key center with a large prime number p randomly selected as the order, and G _T represents The multiplicative cyclic group obtained by bilinearly mapping the additive cyclic group G, G×G→G _T , g _m represents the mth generator in the additive cyclic group G, and g _n represents the nth generator in the multiplicative cyclic group G _T Generating elements, p represents a coefficient greater than 2 ^λ , and the value of λ is determined according to the security parameters of the cryptographic system used when the key generation center generates public parameters.

Step 2, generate the public key and private key of the smart home device and the home control center.

Step 2.1, generate and save the private key of the smart home device: sk={x,y,z}, where x, y, z represent three different positive integers randomly selected in [0,p-1] .

Step 2.2, generate and disclose the public key of the smart home device: pk=(h ₁ ,h ₂ ,h ₃ ), where h ₁ =g _m ^x , h ₂ =g _m ^y , h ₃ =e(g _m , g _m ) ^z , e(·) represents the bilinear mapping operation.

Step 3, generate the ciphertext of the real state of the smart home device and the simulated state of the smart home control center.

C₄＝e(g,h₂)^r+s×h₃，r、s分别表示在[0,p-1]中随机选取的两个不同的正整数，M_R表示智能家居设备的真实状态。Step 3.1, generate the ciphertext of the real state of the smart home device: CT _R ＝{C ₀ ,C ₁ ,C ₂ ,C ₃ ,C ₄ }, where C ₀ ＝g _n ^r , C ₁ ＝g _m ^r ,

C ₄ ＝e(g,h ₂ ) ^r+s ×h ₃ , r and s respectively represent two different positive integers randomly selected in [0,p-1], M _R represents the real state of smart home equipment .

C₄′＝e(g_m,h₂)^r′+s′×h₃，r^′、s^′分别表示在[0,p-1]中随机选取的两个不同的正整数，M_S表示智能家居控制中心的模拟状态。Step 3.2, generate the ciphertext of the simulated state of the smart home control center: CT _S ＝{C ₀ ′,C ₁ ′,C ₂ ′,C ₃ ′,C ₄ ′}, where C′ ₀ ＝g _n ^r′ , C ₁ '=g _m ^r' ,

C ₄ ′=e(g _m ,h ₂ ) ^r′+s′ ×h ₃ , r ^′ and s ^′ respectively represent two different positive integers randomly selected in [0,p-1], M _S represents Mock up state of smart home control center.

Send the real state ciphertext CT _R of the smart home device and the simulated state ciphertext CT _S of the smart home control center to the device gateway.

Step 4, the smart home device generates an authorization trapdoor for the device gateway, and sends the trapdoor to the device gateway.

(g_m,M_R)是根据智能家居设备真实状态密文生成，(g_m,M_R)是根据智能家居控制中心模拟状态密文生成。Step 5, the device gateway generates two test elements,

(g _m , M _R ) is generated according to the real state ciphertext of smart home devices, and (g _m , M _R ) is generated according to the simulated state ciphertext of the smart home control center.

Step 6, judge whether the values of the two test elements are equal, if yes, execute step 7 if the detection result is normal, otherwise, execute step 8 if the detection result is abnormal.

Step 7: The device gateway uploads the ciphertext of the real state of the smart home device to the cloud storage.

Step 8, the device gateway sends the detected abnormal result to the smart home control center.

The above description is only a specific example of the present invention, and does not constitute any limitation to the present invention. Obviously, for those skilled in the art, after understanding the content and principle of the present invention, it is possible without departing from the principle of the present invention, In the case of structure, various modifications and changes in form and details are made, but these modifications and changes based on the concept of the present invention are still within the protection scope of the claims of the present invention.

Claims (1)

1. A smart home anomaly detection method based on TV-PKEET, is characterized in that, generates the ciphertext of smart home equipment real state and simulated state, judges whether detection result is normal according to two test elements that equipment gateway generates; The method The specific steps include the following: Step 1, the key generation center generates system public parameters: The key generation center generates public parameters: Γ={G,G _T ,g _m ,g _n ,p}, where G represents the additive cyclic group generated by the key center with an order of a large prime number p randomly selected, G _T Represents the multiplicative cyclic group obtained by bilinearly mapping the additive cyclic group G, G×G→G _T , g _m represents the mth generator in the additive cyclic group G, and g _n represents the multiplicative cyclic group G _T n generating elements, p represents a coefficient greater than 2 ^λ , and the value of λ is determined according to the security parameters of the cryptographic system used when the key generation center generates public parameters; Step 2, generate public and private keys for smart home devices and home control centers: Step 2.1, generate and save the private key of the smart home device: sk={x,y,z}, where x, y, z represent three different positive integers randomly selected in [0,p-1] ; Step 2.2, generate and disclose the public key of the smart home device: pk=(h ₁ ,h ₂ ,h ₃ ), where h ₁ =g _m ^x , h ₂ =g _m ^y , h ₃ =e(g _m , g _m ) ^z , e(·) represents the bilinear mapping operation; Step 3, generate the ciphertext of the real state of the smart home device and the simulated state of the smart home control center: Step 3.1, generate the ciphertext of the real state of the smart home device: CT _R ＝{C ₀ ,C ₁ ,C ₂ ,C ₃ ,C ₄ }, where C ₀ ＝g _n ^r , C ₁ ＝g _m ^r ,

C ₄ ＝e(g _m ,h ₂ ) ^r+s ×h ₃ , r and s respectively represent two different positive integers randomly selected in [0,p-1], M _R represents the real state; Step 3.2, generate the ciphertext of the simulated state of the smart home control center: CT _S ＝{C ₀ ′,C ₁ ′,C ₂ ′,C ₃ ′,C ₄ ′}, where C′ ₀ ＝g _n ^r′ , C ₁ '=g _m ^r' ,

C ₄ ′=e(g _m ,h ₂ ) ^r′+s′ ×h ₃ , r′ and s′ respectively represent two different positive integers randomly selected in [0,p-1], M _S represents The simulated state of the smart home control center; Send the real state ciphertext CT _R of the smart home device and the simulated state ciphertext CT _S of the smart home control center to the device gateway; Step 4, the smart home device sends the generated authorization trapdoor to the device gateway: Step 5, the device gateway generates two test elements,

{g _m , M _R } means the test element generated according to the real state ciphertext of the smart home equipment, {g _m , M _S } means the test element generated according to the simulated state ciphertext of the smart home control center; Step 6, judging whether the values of the two test elements are equal, if so, then the test result is normal, and then step 7 is executed; otherwise, it indicates that the test result is abnormal, and step 8 is executed; Step 7, the device gateway uploads the real state ciphertext of the smart home device to the cloud storage; Step 8, the device gateway sends the detected abnormal result to the smart home control center.

Images